Microsoft today placed a $250,000 bounty on the heads of the authors of Mydoom.B, promising to pay up to anyone providing information resulting in their arrest and conviction.

The move comes after Mydoom.B emerged yesterday as the first mutant of the worm, also known as Novarg. Launched on Monday, MyDoom has rapidly become one of the most virulent worms seen in the wild.

The 'B' mutant is designed to launch a distributed denial of service attack against Microsoft next month using infected computers as hosts.

The SCO Group is facing a similar onslaught from the 'A' variant of MyDoom, and is also offering a $250,000 reward.

The release of the 'B' variant yesterday triggered the first alert from the newly formed US Department of Homeland Security's cyber-alert system.

"This worm is a criminal attack," said Brad Smith, senior vice president and general counsel at Microsoft, in a statement.

"Its intent is to disrupt computer users, but also to keep them from getting to antivirus locations and other sites that could help them. Microsoft wants to help the authorities catch this criminal."

The software giant explained that residents of any country are eligible for the reward, subject to their prevailing local laws.

Microsoft's bounty comes in the wake of its announcement last November that it would be working with representatives of three law enforcement agencies - the FBI, the US Secret Service and Interpol - to offer rewards for the arrest and conviction of virus writers.

Individuals with information about the Mydoom worm or any other worms or viruses should contact the following international law enforcement agencies:

International/Interpol via the Interpol National Central Bureau in any of Interpol's 181 member countries.
www.interpol.int/

FBI or US Secret Service via any local field office.

The Internet Fraud Complaint Center